The present invention relates to the manufacture of razor blades and more particularly to a method and apparatus for the manufacture of a plurality of razor blades in a continuous strip employing a coil of metallic blade stock.
In the manufacture of razor blades it is common practice to employ a single strand of steel blade stock from which a plurality of blades are produced. The strand of blade stock may be wound in a coil, the stock being of the precise width of the finished product. A plurality of openings are stamped into the strand of blade material defining the precise attach points to be employed in retaining the blade in a cartridge or onto a razor handle, and the strand of blade stock is then generally fed through a heat treating oven to harden the strand of material, after which the strand is sharpened and severed at those locations along the length of the strand effective to produce a plurality of unitary blade members.
While the process is successful in mass producing blades of high quality, an increase in efficiency and speed of production would be made possible by employing a continuous strip of blade stock from which more than one strand of blades could be formed, and maintaining the strip of multiple strands in the rolled form during the manufacturing process, including the heat treatment of the stock.
It is known to manufacture a plurality of strands of material from a single strip which is provided in roll form by initially partially severing the various strands in the strip of material, and then maintaining the strip as a unit until separation into its particular strands is required. A method and device for achieving the partial slitting of a strip of metallic material is disclosed in U.S. Pat. No. 4,170,691, issued Oct. 9, 1979, to John W. Rogers, and entitled Steel Metal Web Handling Method, Apparatus, and Coil Construct.
However, the adaptation of the partial slitting of a continuous strip of material to produce a plurality of blades strands is complicated by the fact that the openings defining the attach points as described above must be precisely located relative to the edge of the strand of the material and each strand must itself be of precise dimension when the strands are separated from the strip of material.
It is therefore an object of the present invention to provide a process for manufacturing a plurality of razor blades in a continuous strip wherein a plurality of strands are formed from the strip having the blade attachment opening precisely aligned with the edge dimensions of each of the strands.
A further object of the invention is to provide a process for manufacturing a plurality of razor blades in a continuous strip which is more efficient and economical than the processes of the prior art.
Yet another object of the invention is to provide a machine for partially slitting a continuous strip of razor blade material having a plurality of registration openings located therein which forms a plurality of strands of interconnected blades, the lines of slitting being precisely located to form strands having the openings precisely aligned with the edge of each strand.
Still a further object of the invention is to provide a machine for splitting a continuous strip of razor blade material which has been partially slit to form a plurality of strands of interconnected blades, which machine is effective-to separate each strand at the slit line form in the material.